But Foreign Ministry spokesman Hamid Reza Asefi said Iran had no P-2 centrifuges at military locations.

The IAEA is currently examining Iran's nuclear activities for signs that it might be developing weapons.

Iran insists its nuclear programme is only for civilian purposes and says it made a full declaration to the IAEA in October.

On Tuesday, Iran's Foreign Minister Kamal Kharrazi said Tehran had only been studying designs of a P-2 centrifuge and that the IAEA had been informed about its research.

"The P-2 centrifuge device is a research programme... We try to utilise any new models in the industry," he was quoted as saying.

He also said Iran could meet its own nuclear fuel demands and could supply the fuel to other countries.

Pakistan link

Gas centrifuges - which can be used to make nuclear warheads - spin at supersonic speeds to separate fissile uranium-235 from the non-fissile uranium isotopes.

The diplomats - who were not identified - said preliminary investigations by IAEA inspectors indicated the Iranian components matched drawings of equipment found in Libya and supplied by the clandestine Pakistani network headed by scientist Abdul Qadeer Khan.

The P-2 centrifuge is a Pakistani version of the advanced Western G-2 design and can produce material for use in reactors or bombs.

Iran agreed late last year to a tough inspections regime overseen by the IAEA.

Under the Nuclear Non-Proliferation Treaty, countries are allowed to enrich uranium, but must notify the authority they are doing so.

Iran promised the IAEA in October that it would suspend its uranium enrichment programme.

US President George W Bush has said the world needs tighter restrictions to prevent the spread of nuclear know-how.

Washington said it would give Iran more time fully to disclose its nuclear activities before deciding whether to refer the issue to the United Nations Security Council.